In the telephonic communication systems it is quite common to feed external cables to a central site. At such a central location the wires are routed to terminal blocks from which individual wires lead to individual key units. The terminal blocks and post wire guides are arranged on a supporting panel to provide an organized, orderly array of wires and blocks. Such an arrangement is shown in U.S. Pat. No. 3,573,373 issued in the name of Francis J. Mullin et al on Apr. 6, 1971. The supporting panels are generally positioned in a vertical arrangement for easy access by the installers. One of the difficulties experienced in such an arrangement is that in the presence of large numbers of wires and cables there is a tendency for them to be ejected from their original position between pairs of adjacent post wire guides.